The integumentary system comprises the skin and its appendages. Skin + derivatives= Integument.
It aims to protect the body from various kinds of damage, such as loss of water or damages from outside.
The integumentary system in chordates includes hair, scales, feathers, hooves, and nails.
It may serve to water proof, and protect the deeper tissues.
Excrete wastes, and regulate body temperature.
It is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature.
INTRODUCTION
The jaw (Upper and lower) is any opposable articulated structure at the entrance of the mouth.
It is typically used for grasping and manipulating food.
Jaw suspension means the fusion of upper jaw and lower jaw or skull for efficient biting.
There are different ways in which these attachments are attained depending upon the modifications in visceral arches in vertebrates.
In most vertebrates, the jaws are bony or cartilaginous and oppose vertically.
The vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, and usually bears numerous teeth.
The vertebrate jaw probably originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the Devonian.
It is believed that the hyoid system suspends the jaw from the brain case of the skull, permitting great mobility of the jaws.
The original selective advantage offered by the jaw may not be related to feeding, but rather to increased respiration efficiency.
The jaws were used in the buccal pump (observable in modern fish and amphibians) that pumps water across the gills of fish or air into the lungs in the case of amphibians.
Over evolutionary time the more familiar use of jaws (to humans), in feeding, was selected for and became a very important function in vertebrates. Many teleost fish have substantially modified jaws for suction feeding and jaw protrusion, resulting in highly complex jaws with dozens of bones involved.
Jaw Suspension or Suspensoria:
The method by which the upper and lower jaws are suspended or attached from the chondrocranium is known as jaw suspension or suspensorium.
Amongst the visceral arches, the first (mandibular) arch consists of
= a dorsal palato pterygoquadrate bar forming the upper jaw,
= and ventral Meckel’s cartilage forms the lower jaw.
The second (hyoid) arch consists of = a dorsal hyomandibular supporting and suspending the jaws with the cranium, and a ventral hyoid.
The remaining visceral arches support the gills and are, hence, called branchial arches. Thus, splanchnocranium forms the jaws and suspends them with the chondrocranium.
The integumentary system comprises the skin and its appendages. Skin + derivatives= Integument.
It aims to protect the body from various kinds of damage, such as loss of water or damages from outside.
The integumentary system in chordates includes hair, scales, feathers, hooves, and nails.
It may serve to water proof, and protect the deeper tissues.
Excrete wastes, and regulate body temperature.
It is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature.
INTRODUCTION
The jaw (Upper and lower) is any opposable articulated structure at the entrance of the mouth.
It is typically used for grasping and manipulating food.
Jaw suspension means the fusion of upper jaw and lower jaw or skull for efficient biting.
There are different ways in which these attachments are attained depending upon the modifications in visceral arches in vertebrates.
In most vertebrates, the jaws are bony or cartilaginous and oppose vertically.
The vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, and usually bears numerous teeth.
The vertebrate jaw probably originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the Devonian.
It is believed that the hyoid system suspends the jaw from the brain case of the skull, permitting great mobility of the jaws.
The original selective advantage offered by the jaw may not be related to feeding, but rather to increased respiration efficiency.
The jaws were used in the buccal pump (observable in modern fish and amphibians) that pumps water across the gills of fish or air into the lungs in the case of amphibians.
Over evolutionary time the more familiar use of jaws (to humans), in feeding, was selected for and became a very important function in vertebrates. Many teleost fish have substantially modified jaws for suction feeding and jaw protrusion, resulting in highly complex jaws with dozens of bones involved.
Jaw Suspension or Suspensoria:
The method by which the upper and lower jaws are suspended or attached from the chondrocranium is known as jaw suspension or suspensorium.
Amongst the visceral arches, the first (mandibular) arch consists of
= a dorsal palato pterygoquadrate bar forming the upper jaw,
= and ventral Meckel’s cartilage forms the lower jaw.
The second (hyoid) arch consists of = a dorsal hyomandibular supporting and suspending the jaws with the cranium, and a ventral hyoid.
The remaining visceral arches support the gills and are, hence, called branchial arches. Thus, splanchnocranium forms the jaws and suspends them with the chondrocranium.
ORIGIN OF CHORDATES
Animal kingdom is basically divided into two sub kingdoms:
Non-chordata- including animals without notochord.
Chordata- This comprising animals having notochord or chorda dorsalis.
Chordates were evolved sometime 500 million years ago during Cambrian period (invertebrates were also began to evolve in this period) .
Chamberlain (1900) pointed out that all modern chordates possess glomerular kidneys that are designed to remove excess water from body.
It is believed that Chordates have originated from invertebrates.
It is difficult to determine from which invertebrate group the chordates were developed.
Chordate ancestors were soft bodied animals. Hence they were not preserved as Fossils.
However, early fossils of chordates have all been recovered from marine sediments and even modern protochordates are all marine forms.
Also glomerular kidneys are also found in some marine forms such as myxinoids and sharks. That makes the marine origin of chordates more believable.
Chordates evolved from some deuterostome ancestor (echinoderms, hemichordates, pogonophorans etc.) as they have similarities in embryonic development, type of coelom and larval stages.
Many theories infers origin of chordates, hemichordates and echinoderms from a common ancestor.
Reptiles are a group (Reptilia) of tetrapod animals comprising today's turtles, ... The reptiles were, from the outset of classification, grouped with the amphibians. ... between lizards, birds, and their relatives on the one hand (Sauropsida)
Larval forms and their significance in arthropodaRekha Jalandra
This presentation is all about the larval forms being found in phylum arthropoda. It starts with the introduction of phylum arthropoda and then detailed information about the larval forms and their significance. i have included total 9 larval forms in this presentation.
The vertebrate brain
The vertebrate brain is the main part of the central nervous system. The brain and the spinal cord make up the central nervous system,
In most of the vertebrates the brain is at the front, in the head. It is protected by the skull and close to the main sense organs.
Brains are extremely complex and the part of human and animal body. The brain controls the other organs of the body, either by activating muscles or by causing secretion of chemicals such as hormones and neurotransmitters.
Muscular action allows rapid and coordinated responses to changes in the environment.
The brain of an adult human weights about 1300–1400 grams .
In vertebrates, the spinal cord by itself can cause reflex responses as well as simple movement such as swimming or walking. However, sophisticated control of behaviour requires a centralized brain.
The structure of all vertebrate brains is basically the same.
At the same time, during the course of evolution, the vertebrate brain has undergone changes, and become more effective.
In so-called 'lower' animals, most or all of the brain structure is inherited, and therefore their behaviour is mostly instinctive.
In mammals, and especially in man, the brain is developed further during life by learning. This has the benefit of helping them fit better into their environment. The capacity to learn is seen best in the cerebral cortex.
Three principles
The brain and nervous system is essentially a system which makes connections. It has input from sense organs and output to muscles. It is connected in several ways with the endocrine system, which makes hormones, and the digestive system and sex system. Hormones work slowly, so those changes are gradual.
The brain is a kind of department store. It has, all inter-connected, departments which do different things. They all help each other gather senses.
Much of what the body does is not conscious. Basically, much of the body runs on automatic (breathing, heart beat, hungry, hair growth) adjusted by the autonomic nervous system. The brain, too, does much of its work without a person noticing it. The unconscious mind refers to the brain activities which are hardly ever noticed.
Introduction
Ostracoderms (shell-skinned) are of several groups of extinct, primitive, jawless fishes that were covered in an armour of bony plates.
They appeared in the Cambrian, about 510 million years ago, and became extinct towards the end of the Devonian, about 377 million years ago. They were quite abundant during the upper Silurian and Devonian periods. Most of fossils of Ostracodermi were preserved in the bottom sediments of freshwater streams.
However, the opinion is sharply divided as to whether their habitat was freshwater or marine.
The first fossil fishes that were discovered were ostracoderms.
The Swiss anatomist Louis Agassiz received some fossils of bony armored fish from Scotland in the 1830s.
The ostracoderms resembled the present day cyclostomes (lampreys and hagfishes) in many respects and together with them constitute a special group of jawless vertebrates, the Agnatha.
Characteristics: They use gills exclusively for respiration but not for feeding . Earlier chordates with gills used them for both respiration and feeding. Ostracoderms had separate pharyngeal gill pouches along the side of the head, which were permanently open with no protective operculum. mostly small to medium-sized fishes, protected by a heavy, bony dermal (derived from skin) armor. bottom-dwellers; filter-feeders or grazers. no paired fins, but many with stabilizing paired flaps on either side of head.
(1) Ostracoderms were the first vertebrates.
(2) They were popularly called armoured fishes.
(4) They lived in freshwater.
(5) They were bottom dwellers.
(6) Their body was fish-like and did not exceed 30 cm in size.
(7) Paired fins were absent.
(8) Median and caudal fins were present.
(9) The caudal fin was of heterocercal type.
(10) The head and thorax were covered by heavy armour of bones. It protected ostracoderms from the giant scorpion like arthropods, eurypterids.
(11) Bony skull was well developed.
(12) Mouth was mostly present on the ventral side.
(13) They were having large number of gill slits.
(14) The nervous system had 10 pairs of cranial nerves.
(15) The head had a pair of lateral eyes, and a median pineal eye.
(16) They were filter feeders, feeding like a vacuum cleaner.
(17) The endoskeleton was either bony or cartilaginous.
Define comparative anatomy.
Classifiy the phylum chordata.
Discuss the limb development of tetrapods.
Describe the features of tetrapods.
Explain the structure and function of the limb of tetrapods.
Discuss homology and analogy in relation to the limb of tetrapods.
Presented by Dr. Farhana Taher Sumya
Guided by Dr. Zinnat Ara Yesmin
ORIGIN OF CHORDATES
Animal kingdom is basically divided into two sub kingdoms:
Non-chordata- including animals without notochord.
Chordata- This comprising animals having notochord or chorda dorsalis.
Chordates were evolved sometime 500 million years ago during Cambrian period (invertebrates were also began to evolve in this period) .
Chamberlain (1900) pointed out that all modern chordates possess glomerular kidneys that are designed to remove excess water from body.
It is believed that Chordates have originated from invertebrates.
It is difficult to determine from which invertebrate group the chordates were developed.
Chordate ancestors were soft bodied animals. Hence they were not preserved as Fossils.
However, early fossils of chordates have all been recovered from marine sediments and even modern protochordates are all marine forms.
Also glomerular kidneys are also found in some marine forms such as myxinoids and sharks. That makes the marine origin of chordates more believable.
Chordates evolved from some deuterostome ancestor (echinoderms, hemichordates, pogonophorans etc.) as they have similarities in embryonic development, type of coelom and larval stages.
Many theories infers origin of chordates, hemichordates and echinoderms from a common ancestor.
Reptiles are a group (Reptilia) of tetrapod animals comprising today's turtles, ... The reptiles were, from the outset of classification, grouped with the amphibians. ... between lizards, birds, and their relatives on the one hand (Sauropsida)
Larval forms and their significance in arthropodaRekha Jalandra
This presentation is all about the larval forms being found in phylum arthropoda. It starts with the introduction of phylum arthropoda and then detailed information about the larval forms and their significance. i have included total 9 larval forms in this presentation.
The vertebrate brain
The vertebrate brain is the main part of the central nervous system. The brain and the spinal cord make up the central nervous system,
In most of the vertebrates the brain is at the front, in the head. It is protected by the skull and close to the main sense organs.
Brains are extremely complex and the part of human and animal body. The brain controls the other organs of the body, either by activating muscles or by causing secretion of chemicals such as hormones and neurotransmitters.
Muscular action allows rapid and coordinated responses to changes in the environment.
The brain of an adult human weights about 1300–1400 grams .
In vertebrates, the spinal cord by itself can cause reflex responses as well as simple movement such as swimming or walking. However, sophisticated control of behaviour requires a centralized brain.
The structure of all vertebrate brains is basically the same.
At the same time, during the course of evolution, the vertebrate brain has undergone changes, and become more effective.
In so-called 'lower' animals, most or all of the brain structure is inherited, and therefore their behaviour is mostly instinctive.
In mammals, and especially in man, the brain is developed further during life by learning. This has the benefit of helping them fit better into their environment. The capacity to learn is seen best in the cerebral cortex.
Three principles
The brain and nervous system is essentially a system which makes connections. It has input from sense organs and output to muscles. It is connected in several ways with the endocrine system, which makes hormones, and the digestive system and sex system. Hormones work slowly, so those changes are gradual.
The brain is a kind of department store. It has, all inter-connected, departments which do different things. They all help each other gather senses.
Much of what the body does is not conscious. Basically, much of the body runs on automatic (breathing, heart beat, hungry, hair growth) adjusted by the autonomic nervous system. The brain, too, does much of its work without a person noticing it. The unconscious mind refers to the brain activities which are hardly ever noticed.
Introduction
Ostracoderms (shell-skinned) are of several groups of extinct, primitive, jawless fishes that were covered in an armour of bony plates.
They appeared in the Cambrian, about 510 million years ago, and became extinct towards the end of the Devonian, about 377 million years ago. They were quite abundant during the upper Silurian and Devonian periods. Most of fossils of Ostracodermi were preserved in the bottom sediments of freshwater streams.
However, the opinion is sharply divided as to whether their habitat was freshwater or marine.
The first fossil fishes that were discovered were ostracoderms.
The Swiss anatomist Louis Agassiz received some fossils of bony armored fish from Scotland in the 1830s.
The ostracoderms resembled the present day cyclostomes (lampreys and hagfishes) in many respects and together with them constitute a special group of jawless vertebrates, the Agnatha.
Characteristics: They use gills exclusively for respiration but not for feeding . Earlier chordates with gills used them for both respiration and feeding. Ostracoderms had separate pharyngeal gill pouches along the side of the head, which were permanently open with no protective operculum. mostly small to medium-sized fishes, protected by a heavy, bony dermal (derived from skin) armor. bottom-dwellers; filter-feeders or grazers. no paired fins, but many with stabilizing paired flaps on either side of head.
(1) Ostracoderms were the first vertebrates.
(2) They were popularly called armoured fishes.
(4) They lived in freshwater.
(5) They were bottom dwellers.
(6) Their body was fish-like and did not exceed 30 cm in size.
(7) Paired fins were absent.
(8) Median and caudal fins were present.
(9) The caudal fin was of heterocercal type.
(10) The head and thorax were covered by heavy armour of bones. It protected ostracoderms from the giant scorpion like arthropods, eurypterids.
(11) Bony skull was well developed.
(12) Mouth was mostly present on the ventral side.
(13) They were having large number of gill slits.
(14) The nervous system had 10 pairs of cranial nerves.
(15) The head had a pair of lateral eyes, and a median pineal eye.
(16) They were filter feeders, feeding like a vacuum cleaner.
(17) The endoskeleton was either bony or cartilaginous.
Define comparative anatomy.
Classifiy the phylum chordata.
Discuss the limb development of tetrapods.
Describe the features of tetrapods.
Explain the structure and function of the limb of tetrapods.
Discuss homology and analogy in relation to the limb of tetrapods.
Presented by Dr. Farhana Taher Sumya
Guided by Dr. Zinnat Ara Yesmin
It is skeletal system of human body in detail description. In this ppt gives axial skeleton of body cranium thoracic cage and Vertibral coloumn . i gave structure and function of the bone , parts of axial skeleton with diagram
Description :
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
3. Skeletal System
Most important organ system in the study of
vertebrate morphology.
- Provides reliable information about the
specific adaptations of vertebrates such as
posture and locomotor adaptations
- Tells about other organ systems
- Due to its hardness and durability, skeleton
becomes fossilized and the study of past
vertebrate life is mostly based on fossils
4. Functions
Give shape to the body and support its
weight
Offers a system of levers that aid
muscles to produce contraction
Protects soft parts such as nerves, blood
vessels and other viscera
Two types of skeleton
Exoskeleton (protective structure on
the outside of the body)
Endoskeleton (protective structure
on the inside of the body)
7. Functions
Two separate components
Cranial skeleton or the skull
Postcranial skeleton (axial and
appendicular)
Composed of mineralized connective
tissues ( dentin, enamel, cartilage and
mostly bones)
-mesenchyme differentiated into
scleroblasts which give rise to
osteoblasts, odontoblasts,
chondroblast and ameloblast.
8. Cartilage
- Forms an important part of the endoskeleton in all
vertebrates
- Cartilage is avascular tissue,
- Other types include the elastic cartilage in the external ear
and epiglottis, and fibrous cartilage in the intervertebral discs
and attachment of tendons and ligaments.
- Cartilage is a tough, elastic, fibrous connective tissue found in
various parts of the body, such as the joints, outer ear, and
larynx. A major constituent of the embryonic and young
vertebrate skeleton, it is converted largely to bone with
maturation.
9. Bones
Comprise most of the endoskeleton in
higher vertebrates
Contrary to cartilage, blood vessels and
nerves are present in bony tissues
passing through small Haversian canals.
Haversian canals are located in the bone
tissue at the center of the compact bone
through which blood vessels, nerve
fibres and lymph vessels pass.
10. Bones
Organic component is primarily collagen, which gives
bone great tensile strength
Inorganic components of bone comprise 60% of the dry
weight
Functions:
- Support and movement via attachments for soft tissue
and muscle
- Protects vital organs
- Major site for red marrow for production of blood cells
- Plays a role in metabolism of minerals such as calcium
and phosphorus
11. Bones
2 basic structural types
based on bone tissue
- Compact bone
- Spongy bone or
cancellous bone
Periosteum – dense layer
of connective tissue that
surrounds the bone
14. Chondrocranium
Composed of cartilage which contributes
to the base of the skull, includes the
sense capsule and in most vertebrates, is
replaced by bone
Primary brain case
Surrounds the brain and the special
sense organs
15. Chondrocranium Ossification Centers
Occipital centers - cartilage surrounding
the foramen magnum may be replaced by
as many as four bones: one basioccipital, two
exoccipital, and one supraoccipital
The six centers that we can see on diagram are:
- Basioccipital bone;
- Exoccipital bone (two centers);
- Supraoccipital bone;
- Interparietal bone (two centers).
16. Sphenoid centers from
basisphenoid bone,
presphenoid bone, and the
side walls above
basisphenoid and
presphenoid form
orbitosphenoid,
pleurosphenoid and
alisphenoid.
17. Ethmoid centers tend to remain
cartilaginous and form cribiform plate of
ethmoid and several ethmoturbinal bones
Otic centers – the cartilaginous otic
capsule is replaced in lower vertebrates by
several bones: prootic, opithotic, epiotic
18. Types of Skull Based on Fenestrae (Temporal Openings)
1. Anapsid skull
- The primitive skull, has no temporal fenestra,
possessed by turtles and other primitive reptiles.
2. Diapsid skull
- The diapsid skull has two temporal fenestrae,
possessed by most members of diapsida including
crocodiles, birds and lizards.
19. 3. Euryapsid skull – this is a derived
diapsid
skull where the lower temporal
fenestra is lost
4. Synapsid skull – has one fenestra
located in
a different place than the euryapsid
skull
20. Dermatocranium
Composed of dermal bones that overlie the
chondrocranium and splanchnocranium
Forms the sides and roof of the skull
protecting the brain, it also forms most of
the bony lining of the roof of the mouth
and encases much of the
splanchnocranium
Completes the protective cover of the brain
and jaws
21. Parts of Dermatocranium
Modern fishes and amphibians have simple skull
and the number of dermal bones present is
reduced, some have tended to be lost or fused
In amniotes, dermal bones predominate, forming
most of the braincase and lower jaw; they are
divided into six series of bones.
22. Parts of Dermatocranium
1. Facial Series – encircles the external naris forming
the snout.
2. Orbital series – encircles the eye defining the orbit
3. Temporal series – lies behind the orbit completing
the posterior wall of the braincase
4. Vault series or roofing bones – located across the
top of skull covering the brain beneath
5. Palatal series – dermal bones of the primary palate
covering the roof of the mouth
6. Mandibular series – encases the Meckel’s cartilage
23.
24. Splanchnocranium
An ancient chordate structure associated with the filter feeding surfaces
Arises from the neural crest cells departed from the sides of the neural tube and
migrate into the walls of the pharynx between successive pharyngeal slits
1. Meckel's Cartilage
2. Palatoquadrate
3. Rostrum
4. Labial Cartilage
5. Basihyal Cartilage
6. Ceratohyal Cartilage
7. Hyomandibular Cartilage
8. Ceratobranchial Cartilage
9. Basibranchial Cartilage
10. Hypobranchial Cartilage
11. A. Mandibular Arch
12. B. Hyoid Arch
13. C. Branchial Arch
Figure 2. Articulated chondrocranium and
splanchnocranium
25. Types of Jaw Attachments
1. Paleostylic – characteristic of Agnathans
- None of the arches attach directly to the skull
2. Euautostylic – the earliest jawed condition
- Found in Placoderms and Acanthodians
- The mandibular arch is suspended from the skull by itself without aid from the hyoid arch
3. Amphistylic – found in early sharks, some osteichthyians and crossopterygians
- Attached to the braincase through two primary articulations
- Anteriorly by a ligament connecting the palatoquadrate to the skull
- Posteriorly by the hyomandubula
26. 4. Hyostylic – found in most modern bony fishes
- The mandibular arch is attached to the braincase primarily through the
hyomandibula with the aid of the sympletic bone
5. Metautostylic – found in most amphibians, reptiles and birds.
- Attached to the braincase directly through the quadrate bone
- Formed in the posterior part of the palatoquadrate
27. 6. Craniostylic – found in mammals
- The entire upper jaw is a part of the braincase but the lower jaw called
dentary bone is suspended from the dermal squamosal bone of the
braincase
- The palatoquadrate and Meckel’s cartilages remain cartilaginous exceot at
their posterior ends which becomes the incus and malleus of the middle
ear respectively
28. Postcranial Skeleton
Axial
Appendicular
Function of body skeleton includes
- Protects the viscera
- Contributes to ventilation of the lungs
- Store for various minerals
- Provides rigidity to the body
- Provides series of firm and hinged segments needed for
locomotion in conjunction with the muscles
29. Axial Skeleton
Forms the main axis of the body
Composed of the notochord, vertebral
column, ribs, sternum and skull
30. Notochord
The primitive axial skeleton,
replaced by the vertebral
column
Unsegmented and composed
of dense fibrous connective
tissue
The first skeletal element to
appear in the embryo of
chordates
31. Structure and Development of Vertebral Column
The vertebral column is the
main axial support of vertebrates
A vertebra is composed of a
centrum, one or two arches, and
various processes
It protects the spinal cord and
provides rigidity to the body
32. Types of Vertebra Based on Centra
1. Aspondyly – no centra
2. Monospondyly – with only one centrum per
segment
- Stereospondyly – a monospondylous vertebra
in which the single centrum (intercentrum) is
separate
3. Diplospondyly – with two centra per segment
- Embolomerous – a diplospondylous vertebra in
which the approximate equal-sized centra are
separate
No centra
33. 4. Polyspondyly – with five to six centra per segment
5. Aspidospondyly – the centra and spines are separate
- Rhachitomous – an aspidospondylous vertebra with
numerous separate parts that constitute each
vertebral segment
6. Holospondyly – the centra and spines are fused into
a single bone
-Lepospondyly - a holospondylous vertebra with a
husk-shaped centrum usually pierced by a
notochordal canal.
34. Figure 2.33. Comparison of vertebrae of primitive
tetrapods and modern amniotes. The rachitomous type
(shown also in cross section, X.S.) occurred in
crossopterygians and in the earliest amphibians. B is from
a labyrinthodont in the reptile line. B1 and B2 are from
other labyrinthodonts. Whether the modern amphibian
centrum represents a hypocentrum (diagonal lines) or a
pleurocentrum (stippled) is not certain. The unmarked part
of the vertebra is the neural arch. Adapted, with
permission, from Kent, G. C. 4th ed. Comparative
anatomy of the vertebrates. St. Louis: C. V. Mosby Co.;
1978. [134]
35. Types of Centra Based on Shapes
1. Amphicoelous
2. Procoelous
3. Opisthocoelous
4. Heterocoelous
5. Acoelous
36. Structure and Function of Ribs
Series of cartilaginous or elongated bony
structures served as attachment for the
vertebrae extending into the body wall
- Provide sites for secure muscle
attachment and help suspend the body
- Form a protective case (rib cage) around
viscera
- In Amniotes, contributes to the breathing
mechanism
37. Types of Ribs
1. True ribs – meet ventrally with the
sternum, consist of two jointed segments
Vertebral or costal rib (proximal segment)
Sternal rib (distal segment)
Joint between costal and sternal ribs allows
changes in chest shape during respiration
2. False ribs – articulate with each other but
not with the sternum
3. Floating ribs – do not articulate ventrally
38. Structure and Function of Sternum
A midventral skeletal element that usually articulates with the more anterior
thoracic ribs and with the pectoral girdle
Strictly a tetrapod structure and primarily, and amniote characteristic
- Strengthen the anterior part of the trunk and body wall
- Helps protect the thoracic viscera
- Accommodates muscles of the pectoral limbs
- In amniotes, helps in ventilating the lungs
The sternum forms either paired or midventral primodia that are regarded as
new structures not derived from the pectoral girdle or ribs
40. Structure and Evolution of Median Fins
Occur in all jawless vertebrates and
fishes:
Dorsal fins - located along the
middorsal line.
Anal fins - located between anus and
tail
Caudal Fin
41. DORSAL and ANAL FINS
o Prevent the body from turning around the
vertical axis (yawing) and around the longitudinal
axis (rolling).
o In primitive vertebrates, each fin is supported
within the contour of the body by a series of rod-
like radials or pterygiophores.
o The exposed membrane of fins of CEPHALASPIDS
and some PLACODERMS are supported only by
dorsal scales.
42. CAUDAL FIN
Classified into four types depending on size and shape of the spine.
1. Diphycercal – if the spine is straight to the tip of the tail
with equal dorsal and ventral lobe of the tail. (ex.
Cyclostomes, pleuracanths, and some sarcopterygians)
2. Hypocercal – if the spine tilts downward with longer
ventral lobe than dorsal lobe.(ex.anaspids)
3. Heterocercal – if the spine tilts upward with longer dorsal
lobe than ventral lobe.(ex.cephalaspids, placoderms, most
chondrichthyes, and primitive osteichthyes)
4. Homocercal - if all the fin membrane is posterior to the
spine with equal dorsal and ventral lobe.(ex.all teleosts)
43. Structures and Evolution of Girdles
Girdles of fishes
o the pectoral girdle is older, larger and more complicated
than pelvic girdle.
-It includes one or more cartilage or replacement
bones and several dermal bones derived from ancestral
scales and armour plates.
o Placoderms cartilaginous fins was related to overlying
plates of dermal skeleton.
o Cartiliginous fishes has no dermal elements
Scapulocoracoid – the right and left halves fused in
the midline forming a U-shaped girdle
1.Ceratotrichia
2. Scapulocoracoid Bar
3. Propterygium
4. Mesopterygium
5. Metapterygium
A. Basal Pterygiophores
44. Girdle and Tetrapod
o BIRDS have a bladelike scapula that
is oriented parallel to the spine.
- with large anterior coracoid
that is articulated with the sternum
- the posterior coracoid has
been lost
- two clavicles fuse ventrally
forming the furcula or absent in
some birds.
45. Girdle and Tetrapod
o the only membrane bone retained Therian
Mammals is the clavicle
- The anterior coracoid is completely lost.
- the posterior coracoid fuses to the scapula
forming the coracoid process of the scapula
- the scapula is unique in having spine which
represents its anterior border
- the ventral end of the spine is continued as
the acromion process to articulate with the clavicle.
46. Girdle and Tetrapod
o the pelvic girdle of Tetrapods is much enlarged over that of fishes and
is relatively uniform in basic structure.
-each half of the pelvic girdle is a single cartilaginous unit in the embryo.
-three bones are constant in the adult:
a dorsal ilium, which articulates with one or more sacral vertebrae
an anterior pubis
A posterior ischium
-the bones of one side usually fuse in the adult forming the innominate
bone
-one or both of the ventral bones of the two sides usually articulates of
fuse across the midventral line, the contact is called pelvic symphysis
47. Girdle and tetrapod
Primitive amphibians had a solid,
triangular shaped pelvic girdle with the
ilium forming the apex
- the pubis can be distinguished
from the ischium by having a obturator
foramen that accommodates a nerve.
In FROG, the girdle has a long, anteriorly
inclined ilium and cartilaginous pubis.
48. Girdle and Tetrapod
REPTILES has various shapes patterned after
the basic plan of LABYRINTHODONTS
-the contact with the spine is firmer
-the large pubo-ischiadic fenestrum is present
between the two ventral bones
Birds have a large pelvic girdle that is firmly
attached to the synsacrum
-the long ilium extends both anterior and
posterior to the socket for the femur or
acetabulum: The pubis is turned backward below
the ischium and there is no symphysis
49. Girdle and Tetrapod
Mammals have a long and expanded ilium
extending only forward from the
acetabulum
- the large obturator fenestrum
represents both the obturator foramen and
the pbo-isichiadic fenestrum of the ancestor.
- a symphysis is always present
- MONOTREMES and MARSUPIALS have
epipubic bones that articulate with the
pubic bones extending forward in the
ventral body wall.
50. MISCELLANEOUS BONES
SESAMOID BONE – bones embedded in or interrupting
tendon
the largest is patella or knee cap
Baculum (os penis) – bone in the penis of carnivores,
bats, insectivores, rodents, and some primates
Additional small bones are found in the different
structures among TETRAPODS:
in the eyelids of CROCODILIANS
in the crest of a BIRD
in the snout of PIGS
at the base of the external ear of some RODENTS Baculum of a dog’s penis
51. TYPES of LOCOMOTION IN MAMMALS
posterior limbs provide rapid acceleration and often support the greater
part of the weight.
Types of locomotion
used by Tetrapods:
- GRAVIPORTAL
- CURSORIAL
- VOLANT
- AERIAL
- SALTATORIAL
52. TYPES of LOCOMOTION in MAMMALS
- AQUATIC
- FOSSORIAL
- SCANSORIAL
- ARBOREAL
53. Comparison of Vertebrates
Vertebrates Type of Skull Type of Jaw Attachment
Fishes Euryapsid Paleostylic/Hyostylic/
Amphistylic
Amphibians Anapsid Metautostylic
Reptiles Anapsid Metautostylic
Birds Diapsid Metautostylic
Mammals Synapsid Craniostylic
Type of Skull and Jaw Attachment
54. Girdles and Fins/Limbs
Dorsal and Caudal
Short/long bones
Hindlimbs are larger than forelimbs
Slightly broader and segmented
Uniform and specialized limb structure
55. Centra and Vertebral Column
Vertebrates Types of Centra based on
shape
Regions of Vertebral Column
Fishes Amphicoelus Anterior and Posterior (2)
Amphibians Amphicoelus, Procoelus or
Opisthocoelous
there is little or no regional specialization
of the vertebral column
Reptiles Procoelus 4 or 5 distinct region
Birds Heterocoelus consists of vertebrae, and is divided into
three sections: cervical (11-25) (neck),
Synsacrum (fused vertebrae of the back,
also fused to the hips (pelvis)), and
pygostyle (tail).
Mammals Acocoelus 5 distinct regions: Cervical, Thoracic,
Lumbar, Sacral and Caudal
Trunk and tail
56. Ribs and Sternum
Vertebrates Ribs Sternum
Fishes Dorsal and ventral set Absent
Amphibians Dorsal andventral set Some
(In early amphibians it is absent
xiphisternum; Anurans
omosternum)
Reptiles Cervical ribs Some
Birds Uncinate processes (are
extensions of bone that project
caudally from the vertical
segment of each rib)
Present
(Large:Carina)
Mammals only have distinct ribs on the
thoracic vertebra, although
fixed cervical ribs are also
Present
(sternebrae: modified into
manubrium and xiphisternum)
Most do not have ribs
Flight muscle
57. Girdles and Fins/Limbs
Vertebrates Girdles Fins/Limbs
Cartilaginous Fishes Large pectoral girdle Fins
Bony Fishes Increased girdle Fins
Amphibians Long girdle Limbs
Reptiles Various shapes Limbs
Birds Large pelvic girdle Limbs
Mammals Long and expanded Limbs